In the DESTINY-Breast01 study (NCT03248492), trastuzumab deruxtecan (T-DXd) showed clinical activity in breast cancer patients with BM who had received ≥2 prior anti-HER2-based regimens or who were previously treated with trastuzumab emtansine (T-DM1)10,11. Here, ERBB2 is linked to breast carcinoma.